Tesla Announces Breakthrough in 4680 Battery Production with Dry Cathode Process

Tesla has officially revealed a significant advancement in its next-generation battery technology. The company is now manufacturing its large-format 4680 battery cells using a fully dry electrode process for both the anode and the cathode. This milestone, disclosed in Tesla’s Q4 and full-year 2025 Update Letter, addresses one of the most persistent technical challenges the automaker has been tackling for years.

🚨NEWS Tesla has cracked the dry silicon code for its 4680 battery cell

A new patent shows Tesla solved how to use high silicon in dry electrodes, unlocking higher range, lower cost, and true mass production for future vehicles pic.twitter.com/B6C7J2NpqH

— Muskonomy (@muskonomy) December 20, 2025

What’s New With the Dry Electrode Technology

First introduced during Tesla’s Battery Day presentation in 2020 as a disruptive innovation, the dry electrode method promises to simplify battery manufacturing, reduce the environmental footprint of factories, cut costs, and increase energy density compared with traditional wet-slurry processes. While Tesla had previously implemented dry processing on the anode, achieving the same for the cathode, the positively charged side of the battery, remained elusive until now.

According to the company’s update, both electrodes in the 4680 cells are now produced with the dry process. This confirmation was also highlighted by Bonne Eggleston, Tesla’s Vice President of 4680 batteries, who shared on social media that “both electrodes use our dry process.”

Why This Matters

The importance of this development goes beyond a technical tick-box; solving the dry cathode process has long been viewed as a key step toward scaling mass production of Tesla’s proprietary 4680 cells. The promise of dry electrode technology has been a major factor in Tesla’s strategy to increase vertical integration, reduce production complexity, and ultimately lower costs across its electric vehicle lineup.

Application in Model Y Battery Packs

In the same update, Tesla also revealed that it has started producing battery packs for select Model Y vehicles using its own 4680 cells. By equipping some Model Ys with these domestically produced batteries, Tesla aims to add flexibility to its supply chain, an especially valuable advantage amid ongoing trade and tariff uncertainties.

This move comes at a time when Tesla is preparing to transition its vehicle portfolio, with the Model Y and Model 3 expected to play an increasingly dominant role in overall production as older models like the Model S and Model X are phased out.

Looking Ahead

While the 4680 battery program has faced skepticism and production difficulties in the past, this latest announcement indicates that Tesla’s engineers may have overcome one of the program’s steepest hurdles. Achieving a fully dry electrode process for both anode and cathode, long viewed as the core promise behind the 4680 cell concept, could have meaningful implications for future Tesla vehicles and battery-based energy products.